Atmospheric and surface satellite measurements are usually exploited on daylight to benefit from the Sun light. However, another application of satellite observations is more and more emerging: images of Earth’s dark side to monitor human lights. Night lights are generally a human phenomenon. As such, they can be considered as proxy of living standards and economic activity of our societies. “An illuminated place, sufficient to be detected by an orbiting satellite, represents the substantial influence we have on pushing back the darkness of the night-time sky.” (cf. ESRI on https://storymaps.esri.com/stories/2017/lights-on-lights-out/index.html).

Satellite images of Earth “night lights” have been a curiosity for the public and a tool of fundamental research for at least 25 years. New global maps have been released by NASA’s Goddard Space Flight Center using the NASA-NOAA Suomi National Polar-orbiting Partnership (Suomi-NPP) satellite.

The potential future applications of such products are quite numerous: to aid disaster response, to produce regular power outage maps and integrate the information into recovery efforts by first responders, to monitor unregulated or unreported fishing, reduce light pollution and help protect tropical forests and coastal areas with fragile ecosystems, and to improve global and regional estimates of carbon dioxide and pollutant emissions.

Indeed, impacts due to human activities (e.g. urbanization, out-migration, economic changes etc…) could be then better measured and interpreted with respect to energy (electricity) and the related production technologies. See for example the maps below: monthly NO2 (a key gas pollutant released by fossil-fuel burning activities) concentration in December 2016 as retrieved from the Dutch-Finnish OMI mission, and the night-lights in 2016 from Suomi-NPP. Quite some similar patterns no?